Plating machine and method of plating

ABSTRACT

A plating machine is provided for electroplating work. The machine includes a series of treating stations which comprise electroplating tanks and nonelectroplating tanks. The work has a long horizontal dimension and a short horizontal dimension. Means are provided for orienting the work during the process so that the long horizontal dimension will be at substantially right angles to the direction of travel when the work is treated in a nonelectroplating tank. When the work is treated in an electroplating tank, it is oriented so that the long dimension is substantially parallel to the direction of travel.

United States Patent [72] inventor James Barton Grosse Pointe Woods, Mich. 793,338

Jan. 23, 1969 Oct. 26, 1971 Ionic International, Inc. Warren, Mich.

[211 Appl. No. [22] Filed [45] Patented [73] Assignee [54] PLATING MACHINE AND METHOD OF PLATING 5 Claims, 10 Drawing Figs.

B65g49/00 50 Field ofSearch 204/202, 203, 204, 205, 19s; 214/89 [56] References Cited UNITED STATES PATENTS 2,255,922 9/1941 Finston 204/202 2,341,606 2/1944 Finston.... 204/203 2,387,160 10/1945 Loney 204/202x 2,461,113 2/1949 Friedman 204/2o3x 2,738,321 3/1956 Finston 204/203 2,848,405 8/1958 Lisowski et al. 204/203 FOREIGN PATENTS 591,839 2/ i960 Canada 204/202 929,167 6/1955 Germany 204/202 l,006,234 4/l957 Germany..... 204/203 Primary Examiner-John H. Mack Assistant Examiner-R. J. Fay Altomeys- Elwood .I. Schaffer and Roger J. Drew ABSTRACT: A plating machine is provided for electroplating work. The machine includes a series of treating stations which comprise electroplating tanks and nonelectroplating tanks. The work has a long horizontal dimension and a short horizontal dimension. Means are provided for orienting the work during the process so that the long horizontal dimension will be at substantially right angles to the direction of travel when the work is treated in a nonelectroplating tank. When the work is treated in an electroplating tank, it is oriented so that the long dimension is substantially parallel to the direction of travel.

PATENTEDnm 26 Ian SHEET 10F 5 INVENTOR JAMES BARTON PATENTEUHB 28 ml 3,616,424

SHEET 2 a? 5 INVENTOR JAMES BARTON {I 2f v 477 ATTORNEYS PATENTEDUBI 26 ISII 3 ,6 l 6 424 SHEET 3 UF 5 5( L 32 L u INVENTOR JAMES BARTON PATENTEDnm 26 I97! SHEET 0F 5 FIG.6

INVENTOR JAMES BARTON BY [4 14 a fa 1 l v ATTORNEYS PATENTEDucr 26 I971 SHEET 5 BF 5 28 3O INVENTOR.

JAMES BARTO N 26 FIGIQ AZT ORNEYS PLATIN G MACHINE AND METHOD OF PLATING BACKGROUND OF THE INVENTION Electroplating of metallic parts normally involves dipping the parts into tanks containing solutions for chemically or physically treating the parts both before and after the actual electroplating operation. The work which is to be plated has a short horizontal dimension and a long horizontal dimension. For example, the part itself may be a sheet metal stamping which by its nature has such a short and long horizontal dimension or the work unit may be a racked group of parts, the overall rack having a short and a long horizontal dimen- It is, of course, desirable when designing a plating machine to minimize the floorspace required for the machine. However, when work units as above described are encountered, it has been necessary in the past to provide a plating machine having an overall length somewhat greater than would be necessary if the work could be properly oriented in the various tanks. When work is immersed in a nonelectroplating tank, it is desired to maintain the maximum possible distance between the work units for good fluid flow between the work units. However, when the work is immersed in an electroplating tank, it is desired to have the work be as close together as possible to form a virtually solid wall facing the anode in the tank and it is desired to have the long dimension parallel to the anode for maximum plating efficiency.

In accordance with the present invention, means are provided to orient the work units during the electroplating process so that the work units will be arranged with the long dimension at substantially right angles to the direction of travel in the nonelectroplaing tanks and with the long dimension parallel to the direction of travel and to the anode during the actual plating step.

SUMMARY OF THE INVENTION A plating machine is provided for moving work through a series of treating stations including electroplating tank means and nonelectroplating tank means. The work is oriented on the machine with a long horizontal dimension and a short horizontal dimension. The machine includes a plurality of horizontally spaced-apart carrier assemblies for supporting the work. Conveyor means are provided for moving the carrier assemblies substantially horizontally through the stations. Turnabout means are provided at the juncture of each electroplating and nonelectroplating station to orient the work with the short dimension at substantially right angles to the direction of travel for movement through an electroplating station and with the long dimension at substantially right angles to the direction of travel for movement through a nonelectroplating station. Lifting means are provided for raising and lowering the work into and out of the tanks.

This structure results in a method of electroplating the work wherein each work unit has the long dimension at substantially right angles to the direction of travel to increase the distance between each adjacent work unit when passing through a nonelectroplating tank means and oriented with the long dimension substantially parallel to the direction of travel to decrease the distance between each adjacent work unit when passing through the plating tank means to provide a virtual wall or work parallel to the anode in the plating tank means.

In the drawings:

FIG. 1 is a side elevational view of a plating machine with rotatable racks with portions broken away for the purpose of clarity forming one embodiment of the present invention;

FIG. 2 is a plan view in section taken substantially along the line 2-2 of FIG. 1 looking in the direction of the arrows;

FIG. 3 is an enlarged sectional view illustrating the lifting mechanism for the carrier arm assembly taken substantially along the line 3-3 of FIG. I looking in the direction of the arrows;

FIG. 4 is a side elevational view of the lifting mechanism of FIG. 3 taken substantially along the line 4-4 looking in the direction of the arrows;

FIG. 5 is a sectional view taken substantially along the line 5-5 of FIG. 4 illustrating a turnabout mechanism for turning the load of the carrier arm assembly prior to immersion thereof into a plating tank;

FIG. 6 is a view of a second tumabout mechanism for returning the load to its original position after the plating operation;

FIG. 7 is a plan view of the carrier arm lifting mechanism as viewed in the direction of arrow 7 of FIG. 3;

FIG. 8 is a side elevational view of the carrier arm assembly;

FIG. 9 is an enlarged view in section of the pivotal portion of the carrier arm;

FIG. 10 is a schematic view illustrating turning of the load prior and subsequent to the plating operation.

The plating machine 10 illustrated in FIGS. 1 and 2 includes a plating conveyor which is of the continuous motion type. The conveyor includes a rigid structural framework 12 which supports carrier arm assemblies 20, lifting mechanisms 14 and a forward drive mechanism. The framework 12 is located between two rows 16, 18 comprising a series of treating stations or process tanks. Work is supported by the carrier arm assemblies 20. The carrier arm assemblies 20 are raised and lowered by the lifting mechanisms 14 for immersing and withdrawing the work 22 into and out of the process tanks.

The process tanks include what are termed preplating tanks, plating tanks, and postplating tanks. The preplating tanks, illustratively two in number 24, 26, contain solutions which act on the work either mechanically, as for example, a water rinse, or chemically, as for example an alkaline cleaner, acid rinse or chemical coating as in the zinc immersion process for plating aluminum. The plating tank 28 contains a solution for depositing, electrochemically, a film on the exterior surfaces of the work. The plating tank includes an anode and an electrolytic solution for plating the desired material onto the work. The postplating tank 30, illustratively one in number, again contains a solution for acting on the work, either mechanically or chemically.

The forward drive includes an upper chain 32 (FIG. 4) and a lower chain 34 (FIG. I). As shown in FIG. 2, a drive sprocket 36 is provided at one end of the plating machine 10 for driving the lower chain 34 and an idler sprocket 38 is provided at the other end of the plating machine. Similar idler sprockets are provided for the upper chain 32 (not shown). The sprocket 36 is driven by means of an electric motor 40 and gear reducer 42.

Referring to FIGS. 3, 4, 8 and 9, each carrier arm assembly 20 includes a slide arm 44 which freely rolls on a vertical H- beam 46. The H-beams 46 extend between the upper and lower chains 32, 34, and are carried along therewith during chain movement. The slide arms 44 are U-shaped and are received around the I-i-beams 46. Each slide arm 44 is provided with four rollers 50, 52, 54, 56 which engage the inner surface of the H-beam forward flanges for up-and-down rolling action. A horizontal carrier arm 58 extends outwardly from each slide arm 44 at approximately right angles to the chain drive. A support strut 60 extends between the carrier arm and slide arm to rigidify the structure. Each carrier arm 58 has, at the outer end thereof, a pivotally mounted yoke bar 62 upon which the work 22 is suspended.

Referring to FIGS. 8 and 9, it will be noted that the yoke bar is supported by means of a bracket 64. The bracket 64 has a shaft 66 which extends through a bearing structure 68 provided in the end of the carrier arm 58. The shaft 66 extends through the carrier arm 58 and carries, on its upper end, a cam structure for turning the bracket and yoke bar 62. The cam structure includes an L-shaped member 70 which has a roller 72, 74 at the outer end of each arm. The L-shaped member 70 is fixedly secured to the shaft 66 so that turning of this member, as will be later described, will result in turning of the yoke bar 62 90 in either the clockwise or the counterclockwise direction.

The horizontal carrier assembly 20 is completed by a roller 76 provided on the slide arm 44 and which contacts the outer face of the I-l-beam 46. The roller 76 functions to actuate limit switches at the upper and lower ends of the I-l-beam. The limit switches function to control the lift mechanisms M which perform the task of raising and lowering the work 22 into and out of the various tanks. As shown in FIG. 5, another roller 78 is provided at the upper end of each I-l-beam 46. The rollers 78 ride on a track 80 forming part of the framework 12. The rollers 78 function to actuate limit switches (not shown) which are also in the circuitry of the lift mechanism 14. These limit switches serve to start the lift mechanism in either a motion to move the carrier assemblies 20 upwardly or a motion to move the carrier assemblies downwardly.

Each I-I-beam 46 is provided with a roller 82 at its lower ends (FIG. 3). The rollers 82 ride on a track 84 which forms part of the framework 12. This structure lends vertical support to the I-l-beam and chain structure.

Referring now to FIGS. and 6, the structure for pivoting the work 22 will be described. FIG. 5 illustrates the turnabout mechanism 85 provided at the dividing wall between the preplating tank 26 and plating tank 28. As will be noted, a V- shaped support member 86 is secured to the track 80 and extends outwardly therefrom. A cam plate 88 is supported on the outer portion of the member 86. The cam plate 88 has, on its under side, a groove 90 for the reception of the roller 74.v The groove 90 has a first straight portion 92 which is in alignment with the roller 74 when the roller 74 is in the position illustrated in FIG. 5 with the work 22 being oriented with the long dimension thereof at right angles to the direction of chain drive. A second groove portion 94 extends from the first portion 92 at approximately a 45 angle with respect to the direction of chain drive. A third portion 96 extends from the second portion 94 substantially parallel to the direction of chain drive. As the carrier assembly 20 is moved along its path, the roller 74 will enter the grove 90 and ride in the first portion 92. When the carrier assembly is moved further along, the roller 74 will enter the second portion 94 causing the L- shaped member 70 to pivot in the counterclockwise direction. The roller 74 will then enter the straight portion 96 and exit from the cam plate 88. TI-Ie L-shaped member 70 will then have been pivoted 90 to the position illustrated at the right of the cam plate 88 as viewed in FIG. 5. In this position, the work 22 is oriented with its long dimension parallel to the direction of chain drive. The work 22 may then be lowered into the plating tank 28 for the plating operation.

After the work has passed through the plating tank, it is raised out of the plating tank. A second tumabout mechanism 97 having a cam plate 98 with attendant support structure 100 is provided at the dividing wall between the plating tank 28 and postplating tank 30. The cam plate 98 has a groove 102 which is the reverse of the groove 90. The first portion 106 is parallel to the direction of chain drive and is in alignment with the roller 72 with the L-shaped member 70 oriented to position the work 22 with the long dimension thereof parallel to the direction of chain drive. The second groove portion 108 extends at substantially 45 from the first portion 106 in a direction extending towards the chain drive. The third groove portion 110 is a straight portion substantially parallel to the direction of chain drive. When the roller 72 is carried to the cam plate 98, it will enter the first portion 106 and travel therethrough. As it travels through the second portion 108, the L-shaped member 70 will be caused to pivot in a clockwise direction to again orient the work 22 with the long dimension thereof substantially at right angles to the direction of chain drive. The roller 72 will exit via the portion 110. The work 22 may now be lowered into the postplating tank 30 with the long dimension thereof oriented in the desired direction.

The means for raising and lowering the work 20 into and out of the tanks is best illustrated in FIGS. 3, 4 and 7. As will be there noted, the lifting mechanisms 14 comprise an. hydraulic cylinder 112 which is pivotally mounted at its lower end 114 to the base 116 of the framework 12. The cylinder 112 is a double-acting cylinder and has a piston rod 118 which is extendable and retractable therefrom. The rod 118 has a crossbar 120 at the outer end thereof for engagement with structure associated with the slide arm 44. As will be noted, a bracket 122 is provided on the rear edge of the'leg 124 of the slide arm 44. The bracket 122 has a portion which extends hehind the H-beam 46. A roller 126 extends from the rear portion of the bracket 122. The roller 126 is in alignment with the crossbar 120. A depression 128 is provided in the upper surface of the crossbar to receive the roller 126 firmly and prevent inadvertent movement of the roller out of engagement with the crossbar.

A second hydraulic cylinder 130 is provided on the base 116. The cylinder 130 is also of the double-acting type. The piston rod 132 extends outwardly from the cylinder 130 towards the cylinder 112. A link 134 pivotally connects the outer end of the rod 132 to the lower end of the cylinder 112.

In operation, when one of the carrier assemblies 20 is above the cylinder 112, the cylinder 122 is actuated to extend the piston rod 118 towards the bracket 122. Upon engagement of the crossbar with the roller 126, the carrier assembly 20 is elevated up the H-beam 46 to a position as illustrated in dotted lines in FIG. 3 wherein the work 22 is above the top of the tank. The carrier assembly 20 is maintained in this position as it passes over the dividing wall between adjacent tanks. During horizontal movement of the elevated work, the

cylinder 112 is pivoted along with the work to maintain engagement with the bracket 122 and holds the work in an elevated position. This pivotal movement is accomplished by actuation of the cylinder 130. Actuation of the cylinder causes the rod 132 to be retracted and, via the link 134, pivot the cylinder 112. The rate of retraction of the rod 132 is synchronized with the speed of the chain so that the cylinder will be moved at the same rate as the work 22. When the work has passed over the dividing wall between the tanks, the cylinder 112 is actuated to cause retraction of the rod 118. The work 22 is thus lowered into the next tank. After the work has been immersed in the tank, the cylinder 130 is actuated to cause extension of the rod 132 resulting in the cylinder being positioned back in its original location.

It will be appreciated that other types of lifting mechanisms may be used. For example, the standard chain-driven counterbalanced elevator mechanism in common usage in connection with the dwell-type" conveyor system which involves intermittent motion is satisfactory in connection with the present invention.

FIG. 10 illustrates schematically the operation of the plating machine 10. As will be noted in FIG. 10, the work 22 is first moved into the preplating tank 24 and after is has been acted upon satisfactorily in that tank it is raised therefrom and then moved to and lowered into the second preplating tank 26. After it has been moved through tank 26, it is lifted by means of the lifting mechanism 14 a distance sufficient to clear the top of the tanks and then is pivoted 90 by means of the roller 74 and cam plate 98 so that the long dimension thereof will be parallel to the direction of chain drive. After the work 22 has passed over the dividing wall between the tanks 26, 28, it is lowered into the plating tank 28 by retraction of the piston rod 118 of cylinder 112. When it has moved through the plating tank 28, it is again raised by means of one of the lifting mechanisms 14 out of the plating tank. The work 22 is then pivoted 90 by means of the roller 72 and cam plate 98 to an orientation wherein the long dimension is again perpendicular to the direction of chain drive. The work is then lowered by retraction of the piston rod 118 of cylinder 112 into the postplating tank 30. After the work has been passed through the postplating tank, it is again lifted out of the tank to clear the end wall of the postplating tank 30. After the work has been passed over the end of the tank 30, it is again lowered and it is removed from the carrier assembly 20. New work is then loaded onto the carrier assembly and it proceeds through the treating stations on the opposite side of the plating machine.

What I claim as my invention is:

1. A plating machine for moving work through a series of treating stations including electroplating tank means and nonelectroplating tank means, said work oriented on said machine with a long horizontal dimension and a short horizontal dimension, said machine including a plurality of horizontally spaced-apart carrier assemblies for supporting the work, conveyor means for moving the carrier assemblies substantially horizontally through the stations, turnabout means at the juncture of at least one electroplating to nonelectroplating station to orient the work with said long dimension at substantially right angles to the direction of travel for movement through a nonelectroplating station, additional turnabout means at the juncture of at least one nonelectroplating station to electroplating station to orient the work with said short dimension at substantially right angles to the direction of travel for movement through an electroplating station, said turnabout means comprising a cam structure at each of said junctures, each of said carrier assemblies including a pivotal shaft, hanger means on said shaft for supporting the work, cam follower means on said shaft for engagement with said cam structures for pivoting of the shaft as the carrier assembly moves thereby, said cam structure including first cam means at the juncture of a nonelectroplating to electroplating station operative to pivot said shaft substantially 90 in one direction and second cam means at the juncture on an electroplating station to nonelectroplating station operative to pivot said shaft substantially 90 in the other direction, said cam follower means on said shaft comprising an L-shaped member fixedly secured at the apex thereof to said shaft, a roller rotatably mounted at the outer end of each of the anns of said L-shaped member, one of the arms of said L-shaped member being at substantially right angles to the direction of travel and the other of said arms being substantially parallel to the direction of travel, said first cam means including a cam surface in alignment with the roller on the arm which is substantially at right angles to the direction of travel for engagement therewith to pivot said shaft substantially 90 in one direction whereupon said arm assumes a position substantially parallel to the direction of travel while the other arm assumes a position substantially at right angles to the direction of travel, said second cam means including a cam surface in alignment with the roller on said other arm when said other arm is at substantially right angles to the direction of travel to engage the roller thereon and pivot the L-shaped member back to its original position.

2. A plating machine as defined in claim I and further characterized in that said treating stations include at least one first preplating tank, at least one second electroplating tank, and at least one postplating tank, said cam structure being provided at the juncture between the preplating tank and electroplating tank and at the juncture between said electroplating tank and said postplating tank.

3. A plating machine as defined in claim 1 wherein said carrier assemblies are movably mounted on a substantially vertical H-beam, said l-l-beam being supported by said conveyor means for movement therewith, said carrier assembly including a slide arm having oppositely disposed sets of rollers thereon, said rollers being in rolling engagement with the inner surfaces of a pair of flanges defined by the H-beam and a horizontal-directed carrier arm extending outwardly from the slide am, said pivotal shaft mounted on the outer end of the carrier arm.

4. A plating machine as defined in claim 3 and further characterized in that said conveyor means comprises an upper chain and a lower chain, said H-beam being connected between said chains, a track beneath said H-beams, roller means at the lower end of each H-beam in rolling engagement with said track to support the H-beams and the work load thereon.

5. A plating machine as defined in claim 3 and further characterized in the provision of an additional roller on said slide arms for rolling engagement with the opposite surface of said l-l-beam flanges to engage limit switch means to control the lifting means and to regulate the degree of raising and lowering of the work.

i i i l i UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,616,424 Dated October 26 1971 Inventor-(s) James Barton It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

' Column 3, line 34 "grove" should read --groove--; line 39, "THe should read --The--. Column 4, line 16, "122' should read --1l2--; line 47, "is" should read --it--. Column 5, line 22, "on" should read --0f--.

Signed and sealed this 30th day of May 1972.

(SEAL) At C68 t:

PDWARD 1-I.F;ETCHER JR Commissioner of Patents 

2. A plating machine as defined in claim 1 and further characterized in that said treating stations include at least one first preplating tank, at least one second electroplating tank, and at least one postplating tank, said cam structure being provided at the juncture between the preplating tank and electroplating tank and at the juncture between said electroplating tank and said postplating tank.
 3. A plating machine as defined in claim 1 wherein said carrier assemblies are movably mounted on a substantially vertical H-beam, said H-beam being supported by said conveyor means for movement therewith, said carrier assembly including a slide arm having oppositely disposed sets of rollers thereon, said rollers being in rolling engagement with the inner surfaces of a pair of flanges defined by the H-beam and a horizontal-directed carrier arm extending outwardly from the slide arm, said pivotal shaft mounted on the outer end of the carrier arm.
 4. A plating machine as defined in claim 3 and further characterized in that said conveyor means comprises an upper chain and a lower chain, said H-beam being connected between said chains, a track beneath said H-beams, roller means at the lower end of each H-beam in rolling engagement with said track to support the H-beams and the work load thereon.
 5. A plating machine as defined in claim 3 and further characterized in the provision of an additional roller on said slide arms for rolling engagement with the opposite surface of said H-beam flanges to engage limit switch means to control the lifting means and to regulate the degree of raising and lowering of the work. 